With the release a few weeks ago of ATI's 6900 series still fresh in our
minds, today we have the opportunity to review Sapphire's Radeon HD6950 to see
how it performs in our usual benchmarks as well as other factors which may
appeal to its intended market.

We're back in touch with Sapphire after a long break (before this year the
last Sapphire card we reviewed was their
Radeon 9800 AIW Pro) due to the team going their own way from 2005-2008
before we reformed in 2009. Sapphire have always championed innovation and
quality and these priorities have helped build their reputation and business to
the level where they are the largest manufacturer of ATI cards and in the past,
when we have asked people what brand of graphics card they prefer, Sapphire has
always been the most popular.

A much more detailed list of features can be
found on the Sapphire product page
here. We tend not to copy manufacturer's specs since product pages
change over time and that renders our information inaccurrate.

GPU

Radeon HD 5870

Radeon HD 6850

Radeon HD 6870

Radeon HD 6950

Radeon HD 6970

Die Size

334

230

255

289

389

Shader units

1600

960

1120

1408

1536

Texture Units

80

56

56

88

96

ROPs

32

32

32

32

32

GPU

Cypress

Barts Pro

Barts XT

Cayman

Cayman

Transistors

2154M

2000M

1700M

2640M

2640M

Memory Size

1024
MB

2024MB

2024MB

2048MB

2048MB

Memory Bus Width

256
bit

256
bit

256
bit

256 bit

256 bit

Core Clock

850
MHz

775 MHz

900
MHz

800 MHz

880 MHz

Memory Clock

1200
MHz

900 MHz

1050 MHz

1250 MHz

1375 MHz

Price

$299

$179

$230

$300

$369.99

Looking at the top end of
ATI/AMD's lineup we can see that the Cypress parts that were rendered obsolete by Barts (the
price is so much lower that it doesn't matter if the performance is similar)
being released a month before Cayman are end of line and will vanish as
stocks dry up. The true successor to the 5870/5850 is the 6970/6950, coming
in at a similar price point but with double the memory and a host of new
features.

To see how the 6900 series compares with its
Nvidia competitors:

GPU

Radeon HD 6950

Radeon HD 6970

GeForce GTX 470

GeForce GTX 480

GeForce GTX 570

GeForce GTX 580

Die Size

289

389

529

529

520

520

Shader units

1408

1536

448

480

480

512

Texture Units

88

96

56

60

60

64

ROPs

32

32

40

48

40

48

GPU

Cayman

Cayman

GF100

GF100

GF110

GF110

Transistors

2640M

2640M

3000M

3000M

3000M

3000M

Memory Size

2048MB

2048MB

1280MB

1536MB

1280MB

1536MB

Memory Bus Width

256 bit

256 bit

320
bit

384
bit

320
bit

384
bit

Core Clock

800 MHz

880 MHz

607
MHz

700
MHz

732
MHz

772
MHz

Memory Clock

1250 MHz

1375 MHz

1,215 MHz

1,401 MHz

1,464 MHz

1,544 MHz

Price

$300

$369.99

$279

$449

$349

$509

Die size is almost half of the Nvidia
products and is partially accounted for by the lack of a 320 or 384 bit
memory bus. It will be seen in the months to come whether Nvidia's 384-bit
bus or AMD's 2GB memory is a significant factor in performance. For now the
jury is still out.

The key aspects of the 6900 series are as
follows:

The dies are similar in size so one can
assume that the 6950 has some capability deliberately disabled for product
differentiation or that speed binning results in those that fail the 6970
test to be used as 6950 GPUs (assuming thay meet the criteria for these).
Realistically, a combination of the two policies will be used.

Power consumption is not too bad - crucially
20W at idle is a good figure as the cards are unlikely to be going flat out
all the time and power saving (and noise since fans will spin slowly when
not needed) is an important consideration in total cost of ownership (TCO).

The ventilation grill is
appropriate for the size of fan used and the display options are flexible
enough for all types of user and adequate for enabling Eyefinity either at
the start or as a future upgrade.

One useful feature we like is the dual BIOS
toggle switch. The cards come with 2 BIOS's as standard so that if something
goes wrong while flashing one BIOS, the other can be switched to for
uninterrupted use.

Two 6-pin
connectors are quite sufficient for this card.

The
Architecture

The architecture shows what goes
into the makeup of each GPU. For those who follow VLSI design a more thorough
treatment can be found in white papers on the ATI website.

The
GPU

Moving on to the Sapphire card itself lets start with the box.

It may seem strange to evaluate packaging (some people throw it
away or tear it open) but it says a lot about brand positioning. Sapphire use a
very strudy box with embossed/raised graphics and lettering. Given the lifespan
of modern graphics cards (we've never had a single one go wrong in almost a
decade of normal use) most users will want to keep the boxes safe to make it
easier sell on or give as a gift to friends/relatives when the time comes to
upgrade to a faster model. We much prefer the egg carton used for holding the
card than the usual flimsy carboard inserts or foam that breaks apart when
handled.

The card is 10.5" in length with the fan at the internal end
allowing air to be pushed the full lenth of the card and out the ventilation
slots in the back. This is similar to the reference design.

A double sided heatsink covers the back of the GPU to assist in
heat dissipation but doesn't protrude too far.

One change of note is the moving of the power sockets from the
end of the card to the side. This will be welcomed by those whose cases made it
difficult or even impossible to fit a lengthy card and have room to get the
6-pin power connectors attached. The only drawback is for those with narrow
cases who may find difficulty putting the side back on with wires sticking out from the
6-pin plugs. The vast majority of PC cases in use today, however, are designed
with cooling in mind and will have ample room to the side.

Moving on to the back of the card, most of the dual slot real
estate is taken up with connectors to support a plethora of outputs and enable
the use of 6 monitors in an Eyefinity configuration. We don't have 6 monitors so
for a demonstration of Eyefinity we will have to point readers towards
www.ati.com

What else is included in the box? An HDMI lead of a good length,
a mini-port to HDMI adapter, a DVI to VGA adapter, Crossfire connector and two
cables to allow molex connectors to be used for the 6-pin power requirements if
the PSU does not have 6-pin connectors. A note of caution - if your PSU doesn
not have 6-pin power connectors for PCI-E cards then it is important to make
sure both molex connectors used do not come off the same rail and to know the
capabilities of the PSU by referring to the manual or manufacturers
specifications. If it looks like the power requirements will be exceeded it may
be time to upgrade to a new PSU and relegate the old one to a less demanding
spare machine etc.

We have two main test systems at present and
recently upgraded our Intel one to an i7-2600K we received from Intel for
the Sandy Bridge launch in January. The AMD system has the most powerful
processor currently available in the AMD range.

Test
Results - DX10

Firstly we will start with DX10 testing (the range of DX11 games is still limited at present although many are
in the pipeline for release this year).

3DMark Vantage is a full DirectX 10 compliant synthetic benchmark. It tests
out all of the DirectX 10 abilities of each card to give the user an idea of
where they rank with their graphic card in a collective pool of many users all
over the internet.

The testing was done with the default performance setting for all of the
cards to give an idea where each one stands in the GPU line up.

Setting aside the orange bars (the CPU performance is fairly level as the
only variable during testing is the graphics card) it can be seen that the
performance of the 3 high end cards scales with their product positioning. The
Radeon HD 5850 which has served us so well for over a year is still capable of
putting up a good fight but is now end of line and is about the same price as
the better performing Radeon HD 6870. The Sapphire Radeon HD 6950, currently
priced about 20% higher than the two others shows a nice boost in performance
and we'll see how that translates into real-world benchmarks. The four low cost
alternatives put on a brave face and may appeal to those on a budget while we
wait to see what plans ATI/AMD have for budget cards in the 6XXX series. Intel's
on-chip HD3000 is shown for comparison purposes only to highligh the fact that
built-in graphics still have a long way to go to reach discrete levels of
performance despite the presence of a powerful processor.

Far Cry 2 is still a firm favourite and taxing on any system. The Sapphire
6950 has no trouble leading the pack at any resolution. Frame rates in 3 figures
may seem overkill for some but anyone buying a graphics card today needs to
consider what they are likely to be playing in a year or two unless you upgrade
every product cycle. By contrast the HD3000 is unplayable at any resolution.

HAWX seems to be easy for most systems to handle with playable rates from all
contendors at all resolutions. Even the HD3000 is playable at low resolutions.
We'll have to see how that changes when we move to HAWX 2.

The current darling of horror games provides lots of eye candy and furious
action. As with Far Cry 2 performance in very good but only the 6XXX series
cards can provide triple digit frame rates at all resolutions.

We're in the process of changing our benchmarks to more demanding ones and
appreciate any feedback suggestions.

Test
Results - DX11

DirectX 11 testing will be coming soon and we'll have a dedicated suite of
benchmarks for this (we may even drop the DX10 ones if DX11 takes off in a big
way in the next few months).

Analysis
and Other Benefits

The Radeon 6xxx series is not just about playing faster and ATI want to
emphasize the quality benefits their new technology brings to the mainstream.
One of these is hardware acceleration in video playback and they illustrate this
with Adobe's Flash player with support for hardware acceleration.

The difference is startling and shows how important this feature can be if
widely implemented. Let's hope that ATI keep pestering the relevant software
developers until they all have this level of support by default.

To see the benefits of DX11 that are
unique to the ATI 6XXX series we need to dig further. It’s tricky to test to see how much of
a speed difference DX11 makes as there are few reliable DX11 benchmarks but
as a showcase of DX11 quality the situation is much better. We used Unigine’s
Heaven Benchmark and can only convey the quality to our readers via YouTube.

The improvement in quality is apparent for all to see.

This next video shows the effects of Hardware Tessellation. The technical
white paper on this feature is enough to send the most avid technophile to sleep
but there's no denying the benefits of the end result.

Sapphire have an extensive range of products
aimed at different market segments. The Radeon HD6950 we looked at today is in
their mainstream range. They also have a toxic range (factory overclocked and
higher spec than reference design) and their unique Vapor-X range which uses a
heatpipe design to improve cooling and so allow quieter fans to be used.

The Sapphire Radeon HD 6950 is well designed with
branding to give the feeling of being a member of an exclusive club. Quality is
second to none and over the years, reliability of Sapphire products has been of
the highest standard. Performance is at the higher end for a Radeon HD 6950 card
despite the Sapphire Radeon HD 6950 being one of the most competitively priced
cards of this type from any manufacturer.

If you're in the market for a Radeon HD 6950 the
Sapphire Radeon HD 6950 ticks all the boxes and is tremendous value for money.